Answers queries on Azores fauna and flora.

Notes on the interbreeding of different races of silkworm. [Forwarded with explanatory note by Edward Blyth.]

Australian Leguminosae problem: of 900 species not ten are common to southwest and southeast. No migration; hence either creation or variation.

Himalayan thistles: graded intermediates between large and small English species, "shakes species to their foundations". Similarity of CD’s and his views on species.

Returns CD’s list of Azores plants with information on the distribution of the species added. Encloses a list, extracted from CD’s list, of those plants common to Europe and the Azores that were probably not introduced by man.

Discusses how best to simulate the light at a particular point on the earth’s surface using coloured glass; considers sunlight as composed of three "principles", varying in proportion according to latitude, which affect germination, lignification, and floriation.

Informs CD which colours of glass accelerate germination, lignification, and floriation; advises CD on obtaining such glass and offers his help in any experiments.

Sends a skeleton of a Bengal jungle cock.

Has never heard of trained otters breeding in captivity.

Introduced domestic rabbits are confined to the ports of India.

Canaries and other tame finches and thrushes brought into India do not breed well.

Origin of the domestic canary. Tendency of domesticated birds to produce "top-knot" varieties.

The tame geese of lower Bengal are hybrids; those of upper Bengal are said to be pure Anser cygnoides.

Wild Anser cinereus occur in flocks in the cold season.

Discusses at length different breeds of domestic cats and possible wild progenitors. Wild and domestic cats occasionally interbreed. The Angora variety breeds freely with the common Bengal cat and all stages of intermediates can be found.

Believes pigeons have been bred in India since remote antiquity.

Discusses whether mankind is divided into races or distinct species.

[CD’s notes are an abstract of this letter.]

Gives names of German dealers who provide seed of superior quality.

Is having difficulties marking close species on the list of British plants.

In all his attempts to advance geographical botany he is stopped by the "application and signification of the word ""species"" " the use of which is both "indefinite and variable". He encloses his list of "Categories of Species".

Sends a catalogue of plants [missing] with the close species marked.

Gives extracts from a letter by Thomas Hutton.

Rabbits are kept (generally by Europeans) in the NW. provinces and breed freely. Canaries are not well adapted to the climate. Reports on domestic cats and pigeons of the area. EB gives references to further information on cats, pigeons, and silkworms.

[CD’s notes are an abstract of this letter.]

Close species in large and small genera.

Artificiality of botanical classification.

Comments on the ease with which different species of Felis can be tamed.

Asian species of wild cattle.

Variation in colour of jackals.

Discusses the difficulties of differentiating between varieties and species. EB recommends Herman Schlegel’s definition of species [in Essay on the physiognomy of serpents, trans. T. S. Traill (1843)]. Problems of defining species of wolves and squirrels. Pigeons and doves afford an illustration of "clusters of species, varieties, or races". Various pigeons have local species in different parts of India and Burma, some of which interbreed where their ranges cross; as do the local species of Coracias [see Natural selection, p. 259].

[CD’s notes are an abstract of this memorandum.]

Gives extract from a letter from Capt. R. Tickell: rabbits are not bred by the Burmese; common European and Chinese geese are bred but have probably only recently been introduced.

EB gives references to works illustrating the dog-like instinct of N. American wolves.

Discusses reason and instinct; ascribes both to man and animals. Comments on various instincts, e. g. homing, migratory, parental, constructive, and defensive. Reasoning in animals; cattle learning to overcome fear of passing trains.

Hybrid sterility as an indication of distinct species. Interbreeding as an indication of common parentage.

Enlarges upon details given by J. C. Prichard [in The natural history of man (1843)].

Adaptation of the two-humped camel to cold climates. Camel hybrids.

Doubts that domestic fowl or fancy pigeons have ever reverted to the wild.

Feral horses and cattle of S. America.

Believes the "creole pullets" to be a case of inaccurate description.

Variations in skulls between species of wild boar.

Pigs are so prolific that the species might be expected to cross.

Milk production of cows and goats.

Sheep and goats of lower Bengal.

Indian breeds of horses.

Variation in Asiatic elephants.

Spread of American tropical and subtropical plants in the East.

EB distinguishes between races and artificially-produced breeds.

[CD’s notes are an abstract of this memorandum.]

Forwards two specimens of beans found on north coast of Norway.

Origin of domestic varieties. EB ascribes "abnormal" variations to man’s propagation of casual monstrosities; believes "normal" variations, e.g. European races of cattle, are a consequence of man’s selecting the choicest specimens. Gives examples of "abnormal" variations; they give rise to features that have no counterpart among possible wild progenitors. Divides domestic animals into those whose origin is known and those whose origin is unknown. Considers that the wild progenitors of nearly all domestic birds are known. Fowls and pigeons show many varieties but if propagated abnormalities are ignored each group can be seen to be variations of a single species, the ancestors of which can be recognised without difficulty. Discusses varieties and ancestry of the domestic fowl. Variation in the wild; the ruff shows exceptional variability; other species of birds show variability in size of individuals. Remarks that markings sometimes vary on different sides of the same animal. Comments on the want of regularity in leaf and petal patterns of some plants. Discusses domestic varieties of reindeer and camels. Origin of humped cattle. Reports the rapid spread of a snail in lower Bengal that was introduced as a single pair five or six years previously.

[CD’s notes are an abstract of part of this memorandum. Memorandum originally enclosed with 1760.]

Notes on Lyell’s Principles, vol. 2.

EB does not believe in connecting links between genera; there is no tendency to gradation between groups of animals.

Does not believe shortage of food can directly produce any heritable effect on size.

Comments on significance of variations discussed by Lyell. Variation in dentition and coloration.

Behaviour of elephants and monkeys.

When varieties are crossed EB considers that the form of the offspring, whether intermediate or like one or other of the parents, depends upon how nearly related the parents are.

Thinks that in the struggle for existence hybrids, and varieties generally, must be expected to give way to the "beautiful & minute adaptation" of the pure types.

Colours of Indian birds.

Vitality of seeds.

Variation among palms.

Fauna of Malaysia and New Zealand. Ranges of bird species.

[Memorandum originally enclosed with 1760.]

Expresses his general opinion on the relative closeness of species in large and small genera. Warns that the size of a genus is dependent upon the locality and extent of the flora studied, that definitions of close species are not consistent, and that peculiarities of botanical classification will influence any attempt to assess the comparative closeness of species in different genera.

Answers questions presumably sent in CD’s letter [missing] of 5 Oct 1855 after reading RMcA’s work on the geographical distribution of testaceous Mollusca.

Encloses two sets of notes [see 1761 and 1762]. EB believes that as a general rule species do not inter-mix in nature whereas varieties, descendants of a common stock, do. Origin of varieties. Geographically separated species are sometimes obviously distinct and sometimes apparently identical. EB does not believe that species or races of independent origin need necessarily differ. Local distribution of species of black cockatoo contrasts with the widespread white cockatoo. The occurrence of distinct but related species in different regions of a zoological province, preserved because of geographical barriers. Instances of interspecific hybrids and intraspecific sterility. Local varieties of species. Varieties are subdivisions of the main branches of the tree of organisms, dividing irregularly but remaining independent of the twigs from another branch.